Over the past thirty years, significant attention has been given to the production of ethyl alcohol, or “ethanol,” for use as an alternative fuel. Ethanol not only burns cleaner than fossil fuels, but also can be produced using corn, a renewable resource. At present, an estimated sixty-nine “dry milling” plants in the United States produce over three billion gallons of ethanol per year. Additional plants presently under construction will add hundreds of millions of gallons in an effort to meet the ever-increasing demand.
Besides ethanol, a great deal of attention is presently being given to a newer class of alternative fuels, loosely termed “biodiesel.” Like ethanol, biodiesel is also a clean burning fuel produced from renewable resources, such as animal fats, soybean oil, corn oil, and waste grease from cooking. Although biodiesel contains no petroleum, it can be blended at any level (proportion) with petroleum-based diesel to create a blended fuel. Such blended fuel can be used in existing diesel engines with little or no modifications.
At the present time, feedstocks (i.e., corn, fats, greases, etc.) are collected and transported to regional facilities for conversion to ethanol or biodiesel. From there, the end products are transported to large terminals for mass blending with diesel fuel or gasoline. The resulting mixture is then transported to fueling stations, such as via tanker truck or rail car. There, it is of course manually pumped into the self-contained fuel tanks of vehicles through a nozzle associated with an individual fueling terminal or “gas pump.”
Despite the prevalence of the foregoing model for the past several decades, it is relatively inefficient and inflexible. Although any concentration of ethanol can be used as a gasoline additive, higher concentrations require an adjustment to the engine controls, such as timing. However, the consumer presently has no choice but to use the ethanol-gasoline blend as formulated for delivery to the fueling station.
Additionally, in October 2004, President Bush signed into law a blenders tax credit to stimulate biodiesel production. This law provides that for each gallon of biodiesel blended with petroleum diesel, the blender shall receive a one dollar tax credit for a specific type of oil or fat converted and 50 cents per gallon on others. While the law stimulates interest from the owner of the fuel terminal to use biodiesel due to profit incentives, it does not in any way encourage the interest of the fuel station owner or the individual consumer. If the biodiesel were instead blended at the pump, then the fueling station would receive the tax credit directly and have the ability to pass a portion onto the consumer.
Moreover, the ability to selectively increase the amount of biodiesel used at the service station would encourage consumers to use a greater concentration than might otherwise be selected by the field. Assuming diesel and biodiesel are sold for $2.50 per gallon (including federal and state taxes for each), the influence of the tax credit on particular concentrations is shown in the following table:
B80=20%*$2.5+80%*($2.5−$1)=$1.70 per gallon
B60=40%*$2.5+60%*($2.5−$1)=$1.90 per gallon
B20=20%*$2.5+20%*($2.5−$1)=$2.30 per gallon
B5=95%*$2.5+5%*($2.5−$1)=$2.45 per gallon.
B2=98%*$2.5+2%*($2.5−$1)=$2.48 per gallon
Consequently, the owner of the fueling station would be encouraged to pass a portion of the savings to the end user in order to sell more biodiesel and obtain a higher tax credit.
U.S. Pat. No. 6,422,465 to Miller, the disclosure of which is incorporated herein by reference, discloses a process for custom mixing fuel at the point of purchase. However, the proposal is to use a bar code associated with the vehicle or its fuel tank to determine the blend to be created. A significant disadvantage thus results, since the user is unable to select the proportion of the renewable fuel, and must instead rely on the information contained in the bar code. There is thus no incentive to increase the amount of renewable fuel used in the blend.
Accordingly, a need is identified for a method for blending renewable fuels with petroleum based fuels in a more efficient and effective manner, and preferably at the “point of sale” based on a user-selected proportion of the renewable fuel. The method would encourage the use of such fuels by station owners as well as consumers, and would allow for the particular blend to be selected “at the pump” or otherwise onsite to avoid the need for pre-delivery blending at an offsite location, such as at a regional facility, or otherwise at a fixed concentration ratio. Eliminating this step in the conventional process would significantly reduce costs, which would be passed onto the end consumer. The method would be simple in operation, and could be accomplished using existing technology, thus potentially allowing for the implementation of a relatively low-cost retrofit solution.